1. Field of the Invention
The present invention relates to pressurized chemical dispensers, and more particularly, to pressurized fluid dispensers which utilize a pressure differential created by the passage of a flowing fluid through a device to dispense a chemical into that fluid.
2. Description of the Prior Art
The prior art discloses numerous types of chemical dispensers which are specifically intended to dispense the chemical chlorine into a swimming pool. U.S. Pat. No. 3,412,021 (Paterson) discloses a chemical injection apparatus which is coupled in parallel with a high pressure water line connecting a water pump to a pool filter unit. The vertically disposed chemical dispenser includes an upper section which is positioned above the water inlet line and which stores undissolved solid chemical. The solid chemical is gradually dispensed from the upper section of the dispenser into the lower section where it is dissolved by the flow of water. The output of the chemical dispenser is coupled to a Tee coupling to the primary high pressure water line which connects directly to the input section on the lower portion of a pool filter unit. The tee coupling includes a suction valve which creates suction in order to maintain a flow of water through the chemical dispenser unit into the pool filter.
U.S. Pat. No. 3,864,090 (Richards) discloses a pressurized chemical injection device which includes a plurality of valves and conduits coupled to the lower portion thereof to divert a portion of the water flowing through a pipe into the chemical injection unit. A restrictor valve is coupled in series with the primary water line. An increase in the restriction produced by this valve creates a higher pressure differential across the chemical dispensing unit and increases increases the rate at which the chemical within the chemical dispenser is dispensed into the water line.
U.S. Pat. No. 3,776,274 (Riley) discloses another pressurized chemical injection unit which utilizes a coaxial tee connector which creates a venturi action in the fluid supply line. This venturi action creates a pressure differential across the input and output lines of the chemical reservoir causing the chemical within the reservoir to be dispensed as desired.
U.S. Pat. No. 3,899,425 (Lewis) discloses a combination filter and automatic chlorinator unit for swimming pools. This device provides a plurality of stand pipes, each of which contain one or more annular filter elements. Water is distributed to each of the stand pipes through one set of pipes and is withdrawn from the interior of the stand pipes by another set of pipes.
U.S. Pat. No. 4,115,270 (Phillips) discloses a percolation type pool chlorination unit which causes water to drip through a powered chemical compound. The dispenser unit must be elevated above the water level in the pool and relies on a gravity feed system.
U.S. Pat. No. 3,933,169 (Halley) discloses a jet action chemical feeding apparatus formed in the shape of a cylinder which includes a hollow tubular chemical pallet which is supported by a centrally positioned rod. A jet of water is directed through the inclined interior of the dispenser and serves to dissolve the chemical at a controlled rate.
U.S. Pat. No. 3,612,080 (Schneider) discloses a chemical dispenser apparatus which includes a housing divided into upper and lower chambers. A float is positioned in the lower chamber and operates valves in response to the level of the liquid in the lower chambers.
U.S. Pat. No. 4,056,470 (Carpenter) discloses an automatic chlorinator which is coupled across the pressure and suction lines of a pool pump. This device includes a float valve assembly which assists in controlling the rate of chemical injection.
Lloyd H. King Enterprises of Hopkins, Minn., manufactures and sells a dispenser for solid chemicals which is inserted in series with a swimming pool high pressure water supply line. A dispenser control unit mechanically displaces a solid chemical pellet vertically downward toward the interior of the main water line in order to control the rate of chemical injection. Chem Control Enterprises of San Gabriel, Calif., manufactures and sells a chemical injection unit for swimming pools which is installed in the water return line. This unit is coupled in series with the water return line by a tee connector. The lower end of the valve assembly is exposed to the flow of return water, causing a flow of water around and over the chemical within the feeder body.